Silos are used industrially for the temporary storage of bulk or dump goods in the form of powders or granular products such as grain, coals, cement, animal feed, sand, gravel, fertilizer, etc. The two most common types of silos have cylindrical or square towers, which function as cell or storage space. At the bottom of the cell, the silo is provided with one or more outlet openings where the stored material can be transferred to a transport system or to a truck for transport.
Such silos are already known according to the state of the art. For example, FR 2 541 715 describes a cylindrical silo with a cell bottom having at least two discharge openings, each of which is located at the bottom of an outlet opening with inclined walls; said outlet openings are separated by at least one upright edge which is straight or bent downward in the vertical plane and is formed by the intersecting line of the walls of said outlet openings, all of these outlet openings are situated in a circle with radius R=4/10 of that of the silo, and at least one additional discharge opening which is also at the bottom of an outlet opening with inclined walls and separated from said large outlet openings at least by an elevated edge which is rectilinear or curved, and wherein said additional outlet openings are located outside of said circle with the discharge openings, and are also separated by upright edges.
A similar concept to that described in FR 2 541 715 is shown in U.S. Pat. No. 4,361,254. U.S. Pat. No. 4,361,254 discloses a hopper having a peripheral side wall having upper and lower outlet openings and a cone-shaped body arranged inside the peripheral side wall, which thus defines an annular space for the storage of solid material there between. The lower outlet opening is separated from the cone-shaped body and thus defines an annular discharge point there between.
Finally, the German patent publication DE 1 226 942 describes a first silo for heavy-flowing bulk material with a prismatic or cylindrical upper part which merges into a prismatic base, the circumference of which is described by the upper part, and which contains a cross-shaped roof.
A major problem with silos is the incomplete outflow of the stored material. Such material can decay or degenerate, as a result of which not only the quality of the stored material may be jeopardised, but also creating a risk of infection for all the material stored in the cell of the silo. However, the prior art does not show any silos in which the necessary measures have been taken to impede or at least partly prevent the accumulation of residual material.
The current state of the art does not provide or does not adequately provides a solution to one or more of the above-mentioned problems or shortcomings.